Yu. I. Mikhailov

Bio: Yu. I. Mikhailov is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Thermal decomposition & Hypophosphite. The author has an hindex of 3, co-authored 6 publications receiving 27 citations.

Kinetics of thermal decomposition of ammonium persulfate

Abstract: Kinetics of thermal decomposition of ammonium persulfate was studied by calorimetry and Raman spectroscopy. The values of activation energies of the overall reaction and its individual stages were estimated.

Obtaining Metallic Bismuth in Condensed Media Composed of Formates

Abstract: Microcrystalline metallic bismuth powders of varied morphology were obtained by reduction of bismuth precursors, basic bismuth formate and bismuth(III) formate in benzyl alcohol, hydrazine hydrate, and sodium borohydride. The methods of X-ray diffraction analysis, scanning electron microscopy, thermogravimetry, and differential scanning calorimetry were used to examine the phase composition and the morphology of the resulting metallic bismuth powders. A dispersion analysis of bismuth samples was made by the method of small-angle scattering of light for a proximate monitoring of the particle size in powders of different fractions. The specific surface area of the metallic bismuth sample was determined by the thermal desorption of argon.

Solar-driven, highly sustained splitting of seawater into hydrogen and oxygen fuels

Abstract: Electrolysis of water to generate hydrogen fuel is an attractive renewable energy storage technology. However, grid-scale freshwater electrolysis would put a heavy strain on vital water resources. Developing cheap electrocatalysts and electrodes that can sustain seawater splitting without chloride corrosion could address the water scarcity issue. Here we present a multilayer anode consisting of a nickel–iron hydroxide (NiFe) electrocatalyst layer uniformly coated on a nickel sulfide (NiSx) layer formed on porous Ni foam (NiFe/NiSx-Ni), affording superior catalytic activity and corrosion resistance in solar-driven alkaline seawater electrolysis operating at industrially required current densities (0.4 to 1 A/cm2) over 1,000 h. A continuous, highly oxygen evolution reaction-active NiFe electrocatalyst layer drawing anodic currents toward water oxidation and an in situ-generated polyatomic sulfate and carbonate-rich passivating layers formed in the anode are responsible for chloride repelling and superior corrosion resistance of the salty-water-splitting anode.

Green Strategy Guided by Raman Spectroscopy for the Synthesis of Ammonium Carboxylated Nanocrystalline Cellulose and the Recovery of Byproducts

Abstract: A one-pot green procedure for the treatment of cellulosic biomass with ammonium persulfate (APS) was developed for the synthesis of highly crystalline carboxylated nanocrystalline cellulose (NCC–COOH), an emerging nanomaterial with a plethora of diversified applications. Raman spectroscopy proved applicable for monitoring the fate of APS and its two byproducts during the production of NCC–COOH from microcrystalline cellulose (MCC). The two main byproducts were then identified and quantified as ammonium sulfate (AS) and H2SO4 with the latter accounted for 60% of the total sulfate ions in solution. On the basis of such findings, one-step neutralization of H2SO4 and NCC with NH4OH immediately after reaction was implemented for the formation of additional AS, followed by its quantitative recovery by precipitation. This was a very effective and critical step in waste stream management and cost reduction for the large scale production of NCC. In addition, the process resulted in highly crystalline NCC with COO–...

Thermal degradation of organic additives used in colloidal shaping of ceramics investigated by the coupled DTA/TG/MS analysis

Abstract: The paper presents the analysis of thermal decomposition of selected organic additives, which are commonly used in shaping of ceramic materials by colloidal methods. Shaping of ceramics requires using different additives which then are burned out during sintering process. For this reason, the knowledge about thermal degradation of organics used, as well as decomposition products, seems to be very important from the application point of view. The analyzed substances were as follows: diammonium hydrocitrate, citric acid, ammonium salt of acrylic polymer, l-ascorbic acid, N,N,N′,N′-tetramethylethylenediamine, and ammonium persulfate. The thermal analysis has been done on the apparatus coupled with mass spectrometer what allowed to observe what types of gasses are released to the atmosphere during heating. The obtained results showed important differences in thermal degradation of organic additives. It was possible to determine at what temperature regions harmful gases like N2O, NO2, or SO2 are released from the organics and which additives can be treated as environmentally friendly.